Csharp: Treeview check list value

/// <summary>         /// 選擇的節點         /// 塗聚文 20121116         /// 捷為工作室         ///          /// </summary>         /// <param name="sender"></param>         /// <param name="e"></param>         private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)         {  #region  4              if (e.Action != TreeViewAction.Unknown)             {                  //Event call by mouse or key-press                  SetNodeCheckStatus(e.Node, e.Node.Checked);              }             #endregion            }         /// <summary>         /// 選擇的節點         /// </summary>         /// <param name="tn"></param>         /// <param name="Checked"></param>         private void SetNodeCheckStatus(TreeNode tn, bool Checked)         {              if (tn == null) return;              // Check children nodes              foreach (TreeNode tnChild in tn.Nodes)             {                  tnChild.Checked = Checked;                  SetNodeCheckStatus(tnChild, Checked);              }              // Set parent check status              TreeNode tnParent = tn;              int nNodeCount = 0;              while (tnParent.Parent != null)             {                  tnParent = (TreeNode)(tnParent.Parent);                  nNodeCount = 0;                  foreach (TreeNode tnTemp in tnParent.Nodes)                      if (tnTemp.Checked == Checked)                          nNodeCount++;                  if (nNodeCount == tnParent.Nodes.Count)                      tnParent.Checked = Checked;                  else                      tnParent.Checked = false;              }          }           #region  選擇的節點         /// <summary>         /// http://www.codeproject.com/Questions/196856/C-NET-Treeview-Node-Checked         /// http://msdn.microsoft.com/en-us/library/system.windows.forms.treeview.aftercheck.aspx         /// </summary>         /// <param name="treeNode"></param>         /// <param name="nodeChecked"></param>         public void CheckAllChildNodes(TreeNode treeNode, bool nodeChecked)         {             foreach (TreeNode node in treeNode.Nodes)             {                 node.Checked = nodeChecked;                 if (node.Nodes.Count > 0)                 {                     this.CheckAllChildNodes(node, nodeChecked);                 }             }         }         #endregion         /// <summary>         /// 顯示選擇的節點         /// </summary>         /// <param name="sender"></param>         /// <param name="e"></param>         private void button1_Click(object sender, EventArgs e)         {              DataTable dt = new DataTable();             dt.Columns.Add("Uid", typeof(Guid));             dt.Columns.Add("ID", typeof(int));             dt.Columns.Add("Name", typeof(string));             dt.Columns.Add("ParentID", typeof(int));              List<TreeNode> selectedNodes = new List<TreeNode>();             GetSelectedTreeNode(treeView1.Nodes, selectedNodes);             int i = 0;             foreach (TreeNode node in selectedNodes)             {                  if (!string.IsNullOrEmpty(node.ToolTipText))                 {                     dt.Rows.Add(new Guid(node.ToolTipText), node.Name, node.Text,node.Parent.Name);                 }                 i++;             }               dataGridView1.DataSource = dt;                                                            }         /// <summary>         /// 選擇的節點的值         /// </summary>         /// <param name="nodes"></param>         /// <param name="selectedNodes"></param>         void GetSelectedTreeNode(TreeNodeCollection nodes, List<TreeNode> selectedNodes)         {             foreach (TreeNode node in nodes)             {                 if (node.Checked)                 {                     selectedNodes.Add(node);                 }                 GetSelectedTreeNode(node.Nodes, selectedNodes);             }         }